Clinical Utility of COPD Case-Finding Tools in Real-World Outpatient Settings

COPD, x ray
What are the most effective COPD case-finding tools that can be used in resource-limited outpatient settings for earlier detection of COPD?

Various case-finding tools for chronic obstructive pulmonary disease (COPD) are effective in identifying the disease in symptomatic patients at an early stage. Such tools can be especially useful for health care providers in resource-limited outpatient settings, according to study results published in the International Journal of Chronic Obstructive Pulmonary Disease.

In the current multicenter validation study, investigators in Taiwan assessed the real-world performance of several COPD case-finding tools in the outpatient setting. The study enrolled 385 individuals from 26 outpatient clinics in Taiwan, who were examined using the following case-finding tools: the COPD Population Screener (COPD-PS; a 5-item, symptom-based questionnaire); a COPD prediction model (PCOPD; predictive model based on the patient’s age, smoking/pack years, COPD assessment test score, and percent predicted peak expiratory flow rate); and a microspirometer (ie, a smartphone-based spirometer). All microspirometer readings were subsequently confirmed with a standard spirometer, which was also used to confirm the COPD diagnosis. Global Initiative for Chronic Obstructive Lung Disease (GOLD) definitions were used to diagnose COPD and to classify disease severity.

Among the 385 study participants, 26.23% (101 of 385) had COPD and 73.77% (284 of 385) had not previously been diagnosed with COPD but were at risk for the disease. All participant were at least 40 years of age, had a smoking history of at least 10 pack-years, and at least 1 respiratory symptom.

In evaluating the efficacy of the COPD case-finding tools, investigators found that use of the microspirometer was associated with a higher area under the curve (AUC) value (AUC, 0.908; 95% CI, 0.87-0.95) than either the PCOPD model (AUC, 0.788; 95% CI, 0.74-0.84) or the COPD-PS questionnaire (AUC, 0.726; 95% CI, 0.67-0.78). The investigators also found that the microspirometry-derived forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio threshold of 74% for determining COPD had superior clinical utility to the measures used by either the PCOPD model or the COPD-PS questionnaire.

The researchers concluded that of the COPD case-finding tools studied, “microspirometry was more accurate and had higher clinical utility,” whereas the PCOPD model and COPD-PS questionnaire “were useful for identifying symptomatic patients likely to have COPD.” They further recommended the COPD-PS as a pretest for microspirometry. “High specificity may be needed when choosing the most suitable alternative COPD case-finding tool,” the researchers noted.


Chen C-Z, Sheu C-C, Cheng S-L, et al. Performance and clinical utility of various chronic obstructive pulmonary disease case-finding tools. Int J Chron Obstruct Pulmon Dis. 2021;16:3405-3415. doi:10.2147/COPD.S339340